"When times get bad, account placements generally go up, but recoveries go down," said Howard Seares, managing general partner at Twenty-First Century Associates in Hackensack. "It might be counterintuitive, but the best times for a collection service are the good times."

Collection agencies typically don't receive fees until they collect their clients' money. Reaching debtors takes time and resources. And with stocks down, joblessness up and access to credit limited, getting people to pay debts has become especially difficult, agencies said.

Often collectors resign themselves to riding out the slow periods and hope their work pays off once the economy improves.

"You're either flooded with business or flooded with payments," said Larry Steller, chief executive officer of Quality Asset Recovery in Gibbsboro, N.J., and former secretary the New Jersey Association of Collection Agencies.

In the year ended Sept. 30, business-to-business accounts placed for collection with members of the Commercial Collection Agency Association rose to a record level, reaching nearly $13.5 billion. At the same time, a survey of members found that 80 percent had seen a decline in collectibility of accounts, with a median drop of 5.6 percent.

Emil Hartleb, the collection group's executive director, said that has prompted more members to work out deals and offer extended payment schedules.

In some cases, Seares' company is extending its 90-day deadlines for commercial and consumer accounts to as much as a year. His normal collection rate is about 40 percent; he said it's too soon to say how much lower that number has gone during the recent market malaise.

Economic hard times can bring opportunities for collection agencies. As an example, for companies forced to reduce staffing, it often makes sense to outsource collection work, said Lisa Freidman, president and co-owner of Allen, Maxwell&Silver Inc. in Englewood Cliffs, N.J.

"We were just out in Silicon Valley and found many companies that had put holds on hiring," she said. "If layoffs are made in the credit departments, they're going to have to cover that function somehow."

On the other hand, as sales drop during downturns, it's sometimes easier for in-house departments to handle delinquent accounts themselves.

Allen, Maxwell&Silver also applies lessons learned during the last economic decline in 2001.

The 17-year-old company began with a specialty in third-party collections, but it expanded into return merchandise authorizations and receivables management. Clients include education book publisher Pearson Education, business gifts provider Myron Corp. and medical device maker Datascope Corp.

"We saw it was important to not be rooted in just one area," Freidman said.

Pressure to recover debt can push agents at times to employ tough tactics. Last year, nearly 71,000 people filed complaints with the Federal Trade Commission about harassing behavior by debt collectors, up from about 69,000 in 2006. Those numbers were the highest for all categories of consumer complaints.

Regulators and consumer groups said the rise reflects the number of Americans who took on heavy debt during the easy-credit days that preceded the current decline. About 4.5 percent of all bank-issued consumer credit cards were delinquent in the second quarter of 2008, versus 2.4 percent in 1990, according to the American Bankers Association.

The complaints also are being attributed to the growth in the number of companies that buy up bad consumer debt at a discount and try to collect whatever they can.

What is harder to quantify is how often debtors lash out at agents, who are barred by law from responding in kind. "Our collectors get cursed at, threatened and vilified on a regular basis," Seares said.

Many in the industry said employing threatening tactics is counterproductive, anyway. Better results come from listening and trying to understand each debtor's plight, Seares said.

"At times like this, we're more apt to be sensitive to people's situation," he said. "After all, we're all in this economic tide moving up and down."